Fundamentals for Recording Great Heart Rate Data: Subject Preparation

Electrocardiography (ECG) or EKG is one of the most commonly recorded signals as it can be used for a wide variety of heart related analysis. Acquiring good, clean data from subjects can prove difficult though. Everything from electrode options to hardware settings can influence ECG signal quality over research. The following guidelines provide a baseline for ECG recording setups to ensure accurate and quality data from participants.

The most common question when recording ECG data is where to place electrodes on the subject. Certain aspects of your research will help inform exactly where to place electrodes. The most important question to answer is what tasks are your participants performing.

For most studies, the ECG placement can be placed by following Einthoven’s Triangle. This incorporates 3 leads; one running along the top of the chest, one running from right should toward left leg, and one running from left shoulder toward right leg. Place electrodes on the clavicle, wrists, or ankles. Note that if participants are moving around, placing on the wrists and ankles can prove difficult so place them instead on the chest area.

Always make sure to prepare your subject before placing electrodes on them. Abrade the skin before placement especially if placing on the wrists or ankles. Double check that the electrode is fresh and apply gel to the electrode for optimal adhesion. About 5-10 minutes after placement, use an impedance checker to check the electrode signal quality. These simple steps can make the difference between clean and noisy data.

If participants have been prepared correctly and the hardware is dialed in, the ECG waveform should resemble the classic ECG example. There are three primary elements to the electrical signal coming from the heart: P-wave, R-wave, and T-wave. Most lead configurations will resemble this waveform example.

ECG Waveform

These simple, but key guidelines will help ensure that ECG signals recorded from subjects are clean and high quality. Attach electrodes at the right parts of the body given the tasks that the participants will perform. Always make sure electrode sites are clean and that the electrodes are fresh. For more information and further instructions on recording ECG, visit the BIOPAC ECG applications page, ECG video tutorials, or view our ECG webinars.

BIOPAC offers a variety of wired and wireless equipment that can be used in ECG studies. To find more information on solutions for recording and analyzing signals such as ECG, heart rate, and respiration using the MP160 and other platforms, you can visit the individualapplication pages on the BIOPAC website.